Sensitized and supersensitized photographic emulsions



June 1954 A. E. VAN DORMAEL ETAL 86 SENSITIZED AND SUPERSENSITIZED PHOTOGRAPHIC EMULSIONS Filed Jan. 51, 1950 2 Sheets-Sheet 1 A=A comouno 0F FORMULA I. F 1B=A DYE OF FORMULA 11.

lg. .cnns comouno OF FORMULA '1 Wm: THE DYE o|= FORMULA x1.

700 no 600 55a 50a 45a 400 11/4 D=A COMPOUND 0F FORMULA EDI.

F E=A 0v: OF FORMULA 2x 1.

{9 arm: COMPOUND OF FORMULA 2111 WITH THE DYE OF FORMULA XII.

G=A COMPOUND OF FORMULA Y. F 5 HaA DYE OF FORMULA XIII.

lg urns COMPOUND OF FORMULA Y WITH Tl-IE nvs OF FORMULA x111.

June 1954 A. E. VAN DORMAEL ETAL 2,680,686

SENSITIZED AND SUPERSENSITIZED PHOTOdRAPI-IIC EMULSIONS Filed Jan. 31, 1950 2 Sheets-Sheet 2 J: A compouno OF FORMULA I. F 4 K=A DYE OF FORMULA m.

19 Lg'l'l-lE COMPOUND OF FORMULA '1 WITH me we or FORMULA m.

700 650 50a 55a 500 450 400 m,

M=A COMPOUND OF FORMULA 1:. N=A DYE or: FORMULA 12m.

19 0.11:1: COMPOUND OF FORMULA 1x WITH THE we or FORMU y In wen/or:

r/Ynar/ fm/ r a Za/vnae/ Jean #74? I Patented June 8, 1954 FICE SENSITIZED AND SUPERSENSITIZED PHOTOGRAPHIC EMULSION S Andr Emile Van Dormael, Heverlee-Louvain, Jean Marie Nys, Louvain, and Arthur Henri De Cat, Kessel-Loo-Louvain, Belgium, assignors to Gevaert Photo-Producten, N. V., Mortsel, Belgium, a Belgian company Application January 31, 1950, Serial No. 141,601

Claims priority, application France February 1, 1949 The present invention relates to a process for the production of photographic silver halide emulsions.

This invention more particularly relates to the sensitization and supersensitization of photographic silver halide emulsions.

An object of the present invention is to provide a new process for sensitizing and supersonsitizing photographic emulsions.

A further object is to provide a photographic element comprising an emulsion sensitized or supersensitized according to our new process.

Other objects will appear from the following description.

We have found that the sensitivity of photographic silver halide emulsions optionally containing optical sensitizers may be improved by incorporating into these emulsions products corresponding to the following general formula Dzthe atoms necessary to complete a member selected from the group consisting of fiveand six-membered heterocyclic nuclei and fiveand six-membered heterocyclic nuclei bearing a fused-on arylene ring,

2 Claims. (Cl. 95-7) or of the corresponding amino-cyclammonium salt corresponding to the formula wherein Xzan acid residue, with an ester, an anhydride or an acid chloride of an aliphatic, aromatic or heterocyclic acid.

The derivatives of the first given general formula wherein R:an amido group may be obtained by causing an. acid chloride or an amide of carbonic acid, such as phosgene, urea or the derivatives of the later, to react upon the products corresponding to the formula The following examples serve to illustrate the invention without limiting, however, the scope thereof.

Example 1 A silver bromo-iodide emulsion, containing per kg. of emulsion 10 mg. trimethincyanine of the n=a positive integer of from 1 to 2, formula l om-cm-om -on= "on o C H so Ni N O 2 a 4 Rza member selected from the group consisting of H, alkyl, substituted alkyl, aryl, alkenyl and alkylene, V

R':a member selected from the group consisting of a substituted acyl group, a not substituted acyl-group, a substituted amido group and a not-substituted amido group.

general formula wherein Rzan acyl group, substituted or not, may be obtained for instance by condensation of a base bearing an imino group and corresponding to the formula r'----' R I-'I(-cH=oH I is strongly supersensitized by simultaneously using 30 ing/kg. of the compound of the formula ner: A mixture of 2 g. N-methyl-2-imino-dihydrobenzthiazole and 0.8.. g.: ethyl-malonate is heated at 170 C. for 1.hour. .After cooling, the

product obtained is sucked off and dried. Melting point (after recrystallisation from alcohol): 262-263 0.

" Example 2 55 i' 'lhe spectral sensitivity of-lasilver chloride emulsion is increased by using 50 mg./kg. of the compound of the formula prepared as follows: g. N-phenyl-2-imino-dihydrobenzthiazole in 50 cm. acetic anhydride are heated at boiling temperature. After cooling,

the product is precipitated by water. Melting point (after recrystallisation from alcohol): 149.5-150.5 C.

Example 3 A silver bromo-iodide emulsion, containing per kg. of emulsion 25 mg. trimethincyanine of the formula on; JJ-CH: -OH=C i i C2115 Cil a is supersensitized by simultaneously using 30 mg./kg. of the compound of the formula in Example 2.

Example 4 A silver bromide emulsion, containing per kg. of emulsion 20 mg. cyanine of the formula rig N is supersensitized by simultaneously using 30 mg./kg. of the derivative of the formula S CH:

4 is strongly supersensitized by simultaneously using 30 mg./ kg. of the derivative of the formula Example 6' A silver bromide emulsion, containing per kg. of emulsion mg. trimethincyanine of the formula is supersensitized by simultaneously using mg./kg. of the compound of the formula JHa prepared in the following manner: A mixture of 3.2 g. N-methyl-2-imino-dihydrobenzthiazole and 4.2 g. benzoyl chloride in cm. xylene is refluxed for 3 hours. After cooling, the precipitate formed is recrystallised from diluted alcohol. Melting point: l56.5-l57.5 C.

Example 7 A silver chloride emulsion, containing per kg. of emulsion 20 mg. trimethincyanine of the formula which may be prepared as follows: A suspension of 5 g. N-methyl-2-imino-dihydrobenzthiazole in cm. acetic anhydride is refluxed for 15 minutes. After adding 100 cm. diluted alcohol (70%) the mixture is heated once more at boiling temperature for 5 minutes whereafter the product is precipitated by ice-water. Melting point (after recrystallisation from alcohol) Bil-142 C.

Emample 5 A silver chloride emulsion, containing per kg. of emulsion 6 mg. trimethincyanine of the formula CHa-CHn-CH:

a an. a.

is supersensitized by simultaneously using 30 mg./kg. of the compound of the formula CH:C O CH:

obtained as follows: A mixture of 3 g. N-methyl- 2-imino-dihydrobenzthiazole and 10 cm. ethyl aceto acetate is refluxed for 2 hours. After cooling, the crystals, formed are sucked off. Melting CgHaS O" point (after recrystallisation from alcohol). benzthiazole and 2.10 g, benzoyl chloride in 30 146-147" C. cm. benzene is heated at boiling temperature for Example 8 3 hours in the presence of 1.2 g. pyridine. After complete evaporation, the residue is washed in an A silver chloride emulsion, containing per 6 ice-cold sodium carbonate solution 5% and finally of emulsion 20 mg. trimethincyanine of the recrystallised from alcohol. Melting point: formula 18618'l C.

is supersensitized by simultaneously using 30 mg./kg. of the compound of the formula Example 11 r A silver bromo-iodide emulsion, containing per -s NH: kg. of emulsion mg. trimethincyanine of the L J: formula 20 (1311. T 02115 prepared as follows: A mixture of 3.3 g. N- 01 01 Brmethyl-2-imino-dihydrobenzthiazole and 0.6 g. 'urea is melted at about 180 C. for 1 hour. After Ha CH3 cooling, the product is extracted by boiling water. Aft cooling, the product obtained is Sucked off is strongly supersensitized by simultaneously and recrystallised from alcohol. Melting point: using mgJkgof the compound of the formula 224-226 C.

Example 9 30 A silver chloro-bromide emulsion, containing per kg. of emulsion 10 mg. pentamethincyanine of NH the formula (I:

=NC=0 S S \N/ oH=oH-oH=oH-oH=J 1k NZ 7 N prepared as follows: A mixture of 2.1 g. 2-amino- L 5 40 naphthimidazole and 1.4 g. benzoyl chloride m 50 cm. xylene is heated at boiling temperature for 3 hours in the presence of 0.3 g. pyridine. After complete evaporation, the residue is washed in an ice-cold sodium carbonate solution 5% and recrystallised from alcohol. Melting .point: 244-245 0.

is strongly supersensitized by simultaneously using 30 mg./kg. of the derivative of the formula NH J Example 12 A silver bromo-iodide emulsion, containing per kg. of emulsion 30 mg. trimethincyam'ne of the e formula prepared according to Pierrons indications (Ann.

Chim. (8) 15 (1908) Se CH3 Se Example 10 A? i B A silver chloro-bromide emulsion, containing M \N 7 per kg. of emulsion 20 mg. trimethincyanine of A) the formula 01H, 2H5

om-om-om I O-OH= CH C'HISOF NZ N is strongly supersensitized by simultaneously as is supersensitized by simultaneously using 30 using 30 mg./kg. of the derivative of formula mg./ kg. of the compound of theformula 76 prepared according to sei de s indications (Ber. 58 prepared as follows: A mixture of 2.25 g. 2-amino- (1925) 354) Example13 prepared as follows: A mixture of 4 g. N- A silver bromo-iodide emulsion, containing per methyl'z'lmmo'dihydmbenzthiazole and i i lrdro uinone-diacet lchloride in 45 cm k of emulsion 20 m trimetnmc anme the cm 9 y g g y f xylene 1s refluxed for '3 hours. After cooling, the

formula crystalline product is separated and recrystal- S o H lised from cyclohexanone. Melting point: 276- I 277 C. 01 Cl Example 16 g 5 I 10 A silver chloride emulsion, containing per kg. of emulsion mg. c'yanine according to the is supersensitized by simultaneously using 30 mg./kg. of the compound of the formula formula is supersensitized by simultaneously using 30 m ./k of the com ound of the formula prepared as follows: A mixture of 1.4 g. 2-aminog a p loenzoxazole (according to Skraup, Ann. 419

(1919) 68) and 1.4 g. benzoylchloride in cm. 0 dry benzene, is refluxed for minutes. Then 0.8 5 it g. pyridine are added to the reaction mixture \N/ \N which is further refluxed for 3 hours. After fil- L trating while still warm, the filtrate is cooled and H1 (1133 the precipitate formed is filtrated. Melting point (after recrystallisation from alcohol) 214-215 C. 30 prepared F follows: A m x of methyl-2-1m1no-dihydrobenzth1azo1e and 1.1 g.

Example 14 2 carhethoxymethyl benzthiazole in l cm. A silver chloro-bromide emulsion, containing Xylene, is heated for 4 h s a boiling e p aper kg. of emulsion 10 mg. trimethincyanine of ture in the presence of 5 drops pyridine. After the formula '35 cooling and recrystallising from butanol, a prodr EHPCHZCHE i 1 I c-on: on

is supersensitized by simultaneously using 30 not is obtained, melting at 172-173" (3., and cormg'./kg. of the compound of formula responding to the formula EH3 s s fi =0 L=N-OOCH2 L N N l l 1 V Hs N 2 g. of this compound and 1.12 g. methyliodide are A heated at 100 C. for 48 hours in a sealed tube and a product of the formula prepared according to Camps, Archiv der Pharmazie,240 (1902) 363. g T

0-011 GN=C Example 15 6 1 N I A silver chloro-bromide emulsion, containing 1 5 per kg. of emulsion 10 mg. trimethincyanine of Y a the formula is obtained. Melting point: 253-254 C. (with decm-oHT-om w 3 N -c11= g OH c N 0211580;

is supersensitized by simultaneously using 30 composition). 1 g. of the latter product is dismg./kg. of the compound of the formula solved in 50 cm. phenol and 50 cm. anhydrous S o o S Jags-d-cmm-Oo-om-A-zwl: N \N a.

9 alcohol. After adding 2 g. KOH dissolved in 20 cm. ethanol, the reaction mixture is refluxed for 2 hours. On pouring out into sodium hydroxide N, the azaketomethylene compound corresponding to the formula (EH3 precipitates. Melting point (after recrystallisation from isoamyl alcohol) 326327 C.

The specification is accompanied by drawings to illustrate the supersensitizing efiect obtained with five of our new dyestuff combinations used in silver halide emulsions. Each of the Figs. 1 to 5 is a diagrammatic reproduction of three spectrograms. In each figure, the sensitivity is represented by a dotted line; the sensitivity of the emulsion containing only the cyanine dye is represented by a dash-dotted line; and the sensitivity of the emulsion containing the compound according to the invention in combination with the cyanine dye is represented by the solid line.

We claim:

1. A photographic silver halide emulsion containing the compound of the formula 2. A photographic silver halide emulsion containing the combination of the dyestufi of the formula l0 and the dyestuff of the formula than N References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,080,049 Kendall May 11, 1937 2,153,930 Kendall Apr. 11, 1939 2,177,635 Carroll et a1 Oct. 31, 1939 2,298,732 Brooker et a1. Oct. 13, 1942 2,312,040 Kendall et a1. Feb. 23, 1943 2,340,882 Kendall Feb. 8, 1944 2,490,745 Carroll et a1 Dec. 6, 1949 2,503,861 Weissberger Apr. 11, 1950 FOREIGN PATENTS Number Country Date I 617,720 Great Britain Feb. 10, 1949 

1. A PHOTOGRAPHIC SILVER HALIDE EMULSION CONTAINING THE COMPOUND OF THE FORMULA 